Environmental microbiology is the natural science of microorganisms: their connection with one another and with their environment. It concerns the three major domains of life—Eukaryota, Archaea, and Bacteria—as well as viruses. Biotechnology may be used beside Environmental microbiology to address a number of environmental and economic challenges. For instance, molecular methods such as community fingerprinting can be used to track changes in microbial communities over time or assess their biodiversity.